/*
 * Copyright (c) 2010 Frederic Daoud
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package com.fdaoud.rayures.extension;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.validation.ConstraintViolation;
import net.sourceforge.stripes.action.ActionBean;
import net.sourceforge.stripes.action.ActionBeanContext;
import net.sourceforge.stripes.action.Resolution;
import net.sourceforge.stripes.controller.StripesConstants;
import net.sourceforge.stripes.exception.DefaultExceptionHandler;
import net.sourceforge.stripes.util.Log;
import net.sourceforge.stripes.validation.SimpleError;
import net.sourceforge.stripes.validation.ValidationError;
import net.sourceforge.stripes.validation.ValidationErrors;
import javax.validation.ConstraintViolationException;
import com.fdaoud.rayures.util.JsonUtil;

/**
 * Translates {@link ConstraintViolationException}s into {@link ValidationError}s.
 *
 * @author Frederic Daoud
 */
public class RayuresValidatorExceptionHandler extends DefaultExceptionHandler {

  private static final Log log = Log.getInstance(RayuresValidatorExceptionHandler.class);

  public Resolution handleValidatorException(ConstraintViolationException exc,
    HttpServletRequest request, HttpServletResponse response)
    throws Exception
  {
    ActionBean actionBean = (ActionBean) request.getAttribute(StripesConstants.REQ_ATTR_ACTION_BEAN);

    if (actionBean != null) {
      ActionBeanContext context = actionBean.getContext();
      ValidationErrors errors = context.getValidationErrors();
      Set<ConstraintViolation<?>> violations = exc.getConstraintViolations();
      Map<String,List<String>> map = new HashMap<String,List<String>>();

      for (ConstraintViolation violation : violations) {
        String message = violation.getMessage();
        ValidationError error = new SimpleError(message);
        String field = violation.getPropertyPath().toString();
        errors.add(field, error);

        List<String> mapList = map.get(field);
        if (mapList == null) {
          mapList = new ArrayList<String>();
          map.put(field, mapList);
        }
        mapList.add(message);
      }
      String json = JsonUtil.toJson("errors", map);
      response.setHeader("X-Stripes-Validation-Errors", json);

      log.debug("Created validation errors for fields: ", errors.keySet());

      return context.getSourcePageResolution();
    }
    else {
      throw exc;
    }
  }
}
